add dashes to YAML files

.github/workflows/contributors.yml

@@ -1,3 +1,4 @@
+---
 name: Contributors List
 
 on:
@@ -44,4 +45,4 @@ jobs:
           delete-branch: true
           title: 'chore: update contributors-list'
           body: |
-            Automated update to `images/contributors_list.svg`
+            Automated update to `images/contributors_list.svg`

.github/workflows/hello.yml

@@ -1,3 +1,4 @@
+---
 name: Welcome first time contributors 
 
 on:

.github/workflows/labels.yml

@@ -1,3 +1,4 @@
+---
 name: Import open source standard labels
 
 on:

.github/workflows/rust.yml

@@ -1,3 +1,4 @@
+---
 name: Rust
 
 on:

.github/workflows/rust_format.yml

@@ -1,3 +1,4 @@
+---
 name: Rust format and clippy checks
 on:
   push:

.github/workflows/stale.yml

@@ -1,3 +1,4 @@
+---
 # This workflow warns and then closes issues and PRs that have had no activity for a specified amount of time.
 #
 # You can adjust the behavior by modifying this file.

.mega-linter.yml

@@ -1,3 +1,4 @@
+---
 # Configuration file for MegaLinter
 # See all available variables at https://megalinter.io/configuration/ and in linters documentation
 

docker-compose.yml

@@ -1,3 +1,4 @@
+---
 version: "3.9"
 services:
   app: